[Devel] [PATCH RHEL7 COMMIT] ploop: push_backup: add timeout tunable

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-327.18.2.vz7.14.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.18.2.vz7.14.20
------>
commit b5c5467deed92d543d1c26fba018fc0f5f1418e0
Author: Maxim Patlasov <mpatlasov at virtuozzo.com>
Date:   Mon Jun 27 11:11:23 2016 +0400

    ploop: push_backup: add timeout tunable
    
    The patch adds new ploop tunable: push_backup_timeout.
    It is measured in seconds. The default is 42. The meaning is:
    if a preq sits in pending or reported tree for more than that,
    let's abort push_backup operation.
    
    Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
---
 drivers/block/ploop/sysfs.c | 2 ++
 include/linux/ploop/ploop.h | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ploop/sysfs.c b/drivers/block/ploop/sysfs.c
index 3e794ba..d6dcc83 100644
--- a/drivers/block/ploop/sysfs.c
+++ b/drivers/block/ploop/sysfs.c
@@ -467,6 +467,7 @@ _TUNE_BOOL(disable_user_threshold);
 _TUNE_U32(congestion_high_watermark);
 _TUNE_U32(congestion_low_watermark);
 _TUNE_U32(max_active_requests);
+_TUNE_U32(push_backup_timeout);
 
 
 struct pattr_sysfs_entry {
@@ -526,6 +527,7 @@ static struct attribute *tune_attributes[] = {
 	_A2(congestion_high_watermark),
 	_A2(congestion_low_watermark),
 	_A2(max_active_requests),
+	_A2(push_backup_timeout),
 	NULL
 };
 
diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h
index 6f41570..deee8a7 100644
--- a/include/linux/ploop/ploop.h
+++ b/include/linux/ploop/ploop.h
@@ -316,6 +316,7 @@ struct ploop_tunable
 	int	congestion_high_watermark;
 	int	congestion_low_watermark;
 	int	max_active_requests;
+	int	push_backup_timeout; /* in seconds */
 	unsigned int pass_flushes : 1, pass_fuas : 1,
 		     congestion_detection : 1,
 		     check_zeros : 1,
@@ -340,7 +341,8 @@ struct ploop_tunable
 .pass_flushes = 1, \
 .pass_fuas = 1, \
 .check_zeros = 1, \
-.max_active_requests = DEFAULT_PLOOP_BATCH_ENTRY_QLEN / 2, }
+.max_active_requests = DEFAULT_PLOOP_BATCH_ENTRY_QLEN / 2, \
+.push_backup_timeout = 42, }
 
 struct ploop_stats
 {